/******** * author:upupupCoder * time:2022/3/30 * Website:https://home.cnblogs.com/u/EmbeddedChicken * ******/ #include<iostream> #include<string.h> using namespace std; class MyString { friend ostream& operator<<(ostream&out,const MyString &str); private: char *m_data; public: MyString(const char *str=NULL); MyString(const MyString&other); MyString&operator=(const MyString &other); MyString operator+(const MyString &other); ~MyString(); }; MyString::MyString(const char *str) { if(str) { int length = strlen(str); this->m_data = new char[length+1]; strcpy(this->m_data,str); } else { this->m_data = new char[1]; *this->m_data = '\0'; } } MyString::MyString(const MyString&other) { if(other.m_data) { int length = strlen(other.m_data); this->m_data = new char[length+1]; strcpy(this->m_data,other.m_data); } else { this->m_data = new char[1]; *this->m_data = '\0'; } } MyString::~MyString() { if(this->m_data) { delete[] this->m_data; } } MyString MyString::operator+(const MyString&other) { char *str = new char[strlen(other.m_data)+strlen(this->m_data)+1]; strcpy(str,this->m_data); strcat(str,other.m_data); return str; } MyString &MyString::operator=(const MyString&other) { if(&other!=this) { delete[]this->m_data; int length = strlen(other.m_data); this->m_data=new char[length+1]; strcpy(this->m_data,other.m_data); } return *this; } ostream& operator<<(ostream &out,const MyString&str) { out<<str.m_data; return out; } int main() { MyString s1; MyString s2="123456"; MyString s3=s2; MyString s4("ahhadkl"); MyString s5=s3+s2; cout<<' '<<s1<<' '<<s2<<' '<<s3<<' '<<s4<<' '<<s5<<endl; return 0; }